oil in cylinder

[craigdm]

Bit of a cheeky one this, as its actually on my daughters mini cooper, but I find the mini forum very frustrating!

She came back from Manchester this morning and when she left the motorway the car was firing very lumpy. I put the diagnostic box on it and one of the errors was misfire cylinder 3. Took the plugs out and sure enough number three was very oily, no surprise it was misfiring. Cleaned it up and it's all running smoothly again. First thought was head gasket failure, but its not using oil and the engine oil looks as clean as the day went in. Certainly no sign of Mayo.

Any ideas???

 

[Smartbear]

Broken piston ring?

 

[Ewazix]

Broken piston ring?

or it could be valve stem seal leaking down, first diagnostic will be compression tests. But are you sure it was oil? A non firing cylinder can leave the plug wet and oily looking perhaps due to plug/coil pack problems.

 

[ZedM]

Broken piston ring?

or it could be valve stem seal leaking down, first diagnostic will be compression tests. But are you sure it was oil? A non firing cylinder can leave the plug wet and oily looking perhaps due to plug/coil pack problems.

Good call that .......... and glad to see you've updated your signature. New wheels/tyres combo sounds good.

 

[craigdm]

I think the non-firing cylinder idea. Would explain the symptoms nicely. Oil is as clean as the day it went in so that would discount the Head gasket. Not using any oil, so piston rings should be okay.

Never replaced a coil pack, easy job or not? When I put the plugs back in, I purposely swopped 3 & 4, I was holding out hope that it might just be a broken plug which would be obvious if I remove the plugs again and No.3 is clean.

 

[ronk]

When we're the plugs last changed ?

If it's been a while just put a new set in - unburned fuel and catalytic converters don't mix!

 

[craigdm]

Just ordered 4 new plugs and a new coil pack. £60 all in from Eurocarparts. Fingers crossed, looks like the coil pack is just plug&play.

 

[Stu Boy]

One of these coil packs failed on a friends mini recently, seems quite a common problem, easy to change.

Could it be that the plug was just wet with unburnt fuel, if you had broken rings or leaking valve stem oil seals you would be using oil and it might smoke a bit and would certainly smell if you were to follow the car.

I reckon you've cracked it with the plugs and coils.

 

[EdButler]

One of these coil packs failed on a friends mini recently, seems quite a common problem, easy to change.

Could it be that the plug was just wet with unburnt fuel, if you had broken rings or leaking valve stem oil seals you would be using oil and it might smoke a bit and would certainly smell if you were to follow the car.

I reckon you've cracked it with the plugs and coils.

+1

I recently lost a coil pack - same symptoms as described and the plug 'looked' oily. It didn't smell or feel oily however.

 

[craigdm]

So, changed the plugs and the offending coil pack last night and all seems well.

Strange thing is that the car had been used during the day and ran fine on her 20 trip to the train station. When I removed the offending plug from cylinder 3, it was as clean as the other plugs. No signs of oil/unburnt fuel whatsoever.

It went wrong originally when she came off the motorway after a trip to Manchester, but I can't understand why a coil pack would misbehave and then run okay again. What would be different about a motorway journey, rather than 20 miles down a normal road???

 

[CornishRob]

So, changed the plugs and the offending coil pack last night and all seems well.

Strange thing is that the car had been used during the day and ran fine on her 20 trip to the train station. When I removed the offending plug from cylinder 3, it was as clean as the other plugs. No signs of oil/unburnt fuel whatsoever.

It went wrong originally when she came off the motorway after a trip to Manchester, but I can't understand why a coil pack would misbehave and then run okay again. What would be different about a motorway journey, rather than 20 miles down a normal road???

Electrical intermittent problem. Maybe just starting to fail

 

[Stu Boy]

So, changed the plugs and the offending coil pack last night and all seems well.

Strange thing is that the car had been used during the day and ran fine on her 20 trip to the train station. When I removed the offending plug from cylinder 3, it was as clean as the other plugs. No signs of oil/unburnt fuel whatsoever.

It went wrong originally when she came off the motorway after a trip to Manchester, but I can't understand why a coil pack would misbehave and then run okay again. What would be different about a motorway journey, rather than 20 miles down a normal road???

Electrical intermittent problem. Maybe just starting to fail

As Rob says

 

[craigdm]

Bit of a bugger really, as when the fault originally occurred I swapped the plugs in 3 & 4, and can't remember if I also swapped the coil packs or not... I might have replaced the good one ! :headbang: :headbang: :headbang:

 

[Nictrix]

We have a mini cooper also and over the last 4 weeks have had a stutter/misfire in any gear under 2000rpm.
I had originally put this down to dodgy fuel with possibly water causing the splutter.
After a couple of tankfulls and some cleaner fired through things were no better so started with checking the air filter.
No problems with the filter as all was nice and clean.
Finally picked up a socket to remove the plugs, the gaps were close to double what they should have been (original plugs I think on 68,000 miles) swapped them for NGKs and now all is fine and dandy again.
Funnily enough though cylinder no.3 (looking at the engine 2nd from left?) had a small amount of oil around the plug washer.
The plugs themselves looked a perfect colour and I put the oil down to possibly a drip of oil running in after the oil had been topped up, the plug is next to the oil cap.
I cant believe that the car doesnt use any oil though,ours uses around 1/2 litre every 1000 miles and is quite normal.

 

[Stu Boy]

Oh dear

You could always change all the coils

 

[ronk]

You'll have to wait until the next episode then see which plug is fouled!
Afraid it's back to square one :thumbsdown:

 

[craigdm]

We have a mini cooper also and over the last 4 weeks have had a stutter/misfire in any gear under 2000rpm.
I had originally put this down to dodgy fuel with possibly water causing the splutter.
After a couple of tankfulls and some cleaner fired through things were no better so started with checking the air filter.
No problems with the filter as all was nice and clean.
Finally picked up a socket to remove the plugs, the gaps were close to double what they should have been (original plugs I think on 68,000 miles) swapped them for NGKs and now all is fine and dandy again.
Funnily enough though cylinder no.3 (looking at the engine 2nd from left?) had a small amount of oil around the plug washer.
The plugs themselves looked a perfect colour and I put the oil down to possibly a drip of oil running in after the oil had been topped up, the plug is next to the oil cap.
I cant believe that the car doesnt use any oil though,ours uses around 1/2 litre every 1000 miles and is quite normal.

Think Cylinder 3 is second from right, at least that would tie in with the diagnostics report. Daughters is a 2008 R56 model with 90k on the clock and doesn't use a drop of oil. Interesting story about the plugs.... Fault happened on sunday so I ordered some plugs for collection from Halfords, when I drove down there they informed me that mini plugs are special order and it would be tuesday before they could get any from Europarts. Just happen to work next to Europarts so went there direct on the monday. Surprised somewhere like Halfords would be using Europarts. Halfords price was £12.50/NGK plug, Europarts was £8.50 and I found a 10% off code!

 

[Nictrix]

Bugger, NGK iridiums just cost me £51 from Eurocarparts on Saturday. Beru were around £8 each.
Ours is a 57 R56 with 68,000 miles and since we got it with around 45,000 miles it has steadily used around 1/2 litre every thousand miles.
From what I read it can lose 3 litres before the oil light even comes on.
I did research this and there are stories all over the net that it is normal for using up to a litre every thousand miles.

 

[DPG]

My 2008 CooperS was very lumpy low down. Was using loads of oil too.

Ended up needing the injectors cleaning.